fete/backend/src/main/java/de/fete/config/WebConfig.java

package de.fete.config;

import java.io.IOException;
import java.time.Clock;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.config.annotation.PathMatchConfigurer;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.resource.PathResourceResolver;

/** Configures API path prefix and SPA static resource serving. */
@Configuration
public class WebConfig implements WebMvcConfigurer {

  @Bean
  Clock clock() {
    return Clock.systemDefaultZone();
  }

  @Override
  public void configurePathMatch(PathMatchConfigurer configurer) {
    configurer.addPathPrefix("/api", c -> c.isAnnotationPresent(RestController.class));
  }

  @Override
  public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/**")
        .addResourceLocations("classpath:/static/")
        .resourceChain(true)
        .addResolver(new PathResourceResolver() {
          @Override
          protected Resource getResource(String resourcePath,
              Resource location) throws IOException {
            Resource requested = location.createRelative(resourcePath);
            if (requested.exists() && requested.isReadable()) {
              return requested;
            }
            Resource index = new ClassPathResource("/static/index.html");
            return (index.exists() && index.isReadable()) ? index : null;
          }
        });
  }
}